Armored mayflies have a hard, shield-like plate (notum) covering the thorax and part of the abdomen which offers protection from predators. Typically, the notum covers the gills as far back as the sixth abdominal segment and has two prominent points. Caudal filaments are short and fringed with hairs. Members of this burrowing family are considered collector-gatherers and inhabit pools or runs in sandy streams. Baetiscids swim by tucking their legs under their body and undulating their abdomen and tails.